mineral

Mica (Lepidolite or Muscovite)

Phyllosilicate mineral (KAl2(AlSi3O10)(OH)2 for Muscovite)

AI-generated identification · may be incorrect

Hardness: 2.5-4 (Mohs); Color: Silvery-white, gray, or lilac; Luster: Pearly to vitreous; Crystal Structure: Monoclinic; Cleavage: Perfect basal (peels in sheets); Specific Gravity: 2.82

Hardness: 2
Color: Silvery-white, gray, or lilac
Luster: Pearly to vitreous

Identified June 30, 2026More mineral →

Explore Mica (Lepidolite or Muscovite) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 2.5-4 (Mohs); Color: Silvery-white, gray, or lilac; Luster: Pearly to vitreous; Crystal Structure: Monoclinic; Cleavage: Perfect basal (peels in sheets); Specific Gravity: 2.82

Formation & geological history

Formed in igneous pegmatites or metamorphic rocks like schist and gneiss through hydrothermal processes or regional metamorphism. Often found in continental crust environments.

Uses & applications

Used as an electrical insulator, in cosmetics (sparkle in makeup), in joint compound for drywall, and as a heat-resistant window in stoves (Isinglass).

Geological facts

Mica is unique because it can be split into extremely thin, flexible, transparent sheets. Large sheets of mica were used for windows in Russia before glass became common.

Field identification & locations

Identify in the field by its 'books' of thin, flaky layers that can be peeled with a fingernail. Commonly found in granite-rich areas and mountain belts.